Is Zakat obligatory on an inherited sum of money that the heirs have agreed to deposit in one of their accounts without dividing it, and is Zakat to be paid on the entire amount?

Zakat is obligatory on the amount deposited in the bank if the share of each heir reaches the nisab and a hawl (full lunar year) passes over it, even if the money is in a bank account under the name of one of the heirs. The principle is that the inheritance should be divided according to Islamic law, and each heir has the right to take their full share. An adult of sound mind is permitted to dispose of their share, while the right of a minor or someone not of sound mind is preserved, and their guardian takes charge of disposing of it.